This directory contains the rlbox source from the upstream repo:
https://github.com/PLSysSec/rlbox_sandboxing_api/

Current version: [commit 358fb5bb02a326c631efaebdfb59b0df2ab9c602]

UPDATING:

This in-tree copy can be updated by running
  sh update.sh
from within the third_party/rlbox directory.